Techniques for improving indoor air quality

ABSTRACT

Indoor air quality can be improved by monitoring, with at least one air quality sensor, at least one air quality factor of a target environment. Then, based on the collected air quality factor, a HVAC system or an air purification system can be adjusted in order to more efficiently maintain the indoor air quality. Systems that may be used to improve indoor air quality can contain a photo-catalytic oxidation-based air purification system and can communicate with at least one air quality sensor, other purification systems, HVAC system controllers, or a computer configured to monitor and control the air purification systems and HVAC systems.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/906,730, filed on Nov. 20, 2013, the entirety of which is incorporated by reference herein.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[Not Applicable]

PARTIES TO A JOINT RESEARCH AGREEMENT

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SEQUENCE LISTING

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BACKGROUND OF THE INVENTION

Generally, this application relates to air quality improvements. In particular, this application relates to systems and techniques for improving indoor air quality with reduced energy consumption.

Indoor air quality is important in buildings to maintain occupant health, well-being, and productivity, and potentially avoid liability. One method to improve indoor air quality in buildings is to use outside ventilation air for dilution of the inside air. Unfortunately, this method may be associated with a significant energy load. Buildings that attempt to reduce the outdoor air intake rates to save on energy costs without adequately addressing indoor air quality requirements frequently experience degradation in indoor air quality. As a result, there may be a perceived conflict between energy-efficient ventilation and indoor air quality.

Space conditioning typically includes space heating, space cooling, and ventilation. However, it also can include dehumidification and improvements in indoor air quality levels. Space conditioning may account for a significant share of total primary building energy use. Particularly, ventilation methods that allow for reduced outdoor air intake rates can have an impact on building use. First, reduced outdoor air intake rates may translate into reductions in ventilation fan energy use. Second, reduced outdoor air intake rates can reduce energy use associated with the conditioning of outside ventilation air (e.g., heating, cooling, and dehumidification of outside ventilation air). Outdoor ventilation air requires heating on cold days, which imposes a heating load. On hot days, outdoor ventilation air imposes cooling and, in humid atmospheres, dehumidification loads. The energy for conditioning of outdoor ventilation air may be greater than the energy required by the fans to move the ventilation air. The potential energy savings associated with reduced outdoor air intake rates are typically not readily available and they are also difficult to estimate because they greatly depend on many operating parameters, including local climate, air distribution systems, and whether or not the building uses an economizer or energy recovery.

More specifically, ASHRAE Standard 62.1 defines acceptable indoor air quality as: “air in which there are no known contaminants at harmful concentrations as determined by cognizant authorities and with which a substantial majority (80% or more) of the people exposed do not express dissatisfaction.” Furthermore, the standard defines ventilation as: “the process of supplying air to or removing air from a space for the purpose of controlling air contaminant levels, humidity, or temperature within the space.” But, the standard does not guarantee a healthy environment. It acknowledges that there are many factors that could lead to unacceptable indoor air quality in buildings that meet the standard, including the diversity and distribution of contaminants, the susceptibility and sensitivity of the occupants to airborne contaminants, and the effects of other factors that influence human, comfort and health.

Thus, it can be challenging to design a system for improvement and maintenance of indoor air quality that is energy-efficient without compromising indoor air quality. Therefore, it may be useful to provide systems and techniques for improving indoor air quality that may reduce these issues and other undesirable effects.

BRIEF SUMMARY OF THE APPLICATION

According to techniques of the application, methods are provided for improving indoor air quality of a target environment while substantially decreasing the energy consumed, for example, by HVAC systems, to maintain the air quality of the target environment.

The method comprises monitoring, with at least one air quality sensor, at least one air quality factor of the target environment, wherein the target environment is in communication with an air purification system, the at least one air quality sensor, and at least one supply duct of a HVAC system, and the at least one air quality sensor is in communication with a HVAC system controller of a HVAC system and the air purification system; and based on the at least one air quality factor, adjusting one or more of (a) the fresh air intake on the HVAC system; (b) the fresh air supplied to the target environment by the HVAC system through the at least one supply duct; or (c) the target environment air directed through the air purification system.

In another aspect, this application provides systems for monitoring and controlling the air quality of a target environment that comprise (a) an air purification system comprising a housing having an intake opening and an outflow opening, wherein the housing is configured to accept a photo-catalytic oxidation device that is in communication with the intake and outflow openings; and (b) at least one air quality sensor for monitoring at least one air quality factor of a target environment, wherein the air quality sensor is configured to communicate with the air purification system, a HVAC system controller of the HVAC system, or a computer configured to monitor and control the air purification system and the HVAC system.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

FIGS. 1A-1C illustrate different views of an embodiment of a system for improving the air quality of a target environment, according to techniques of the present application.

FIGS. 2A-2F illustrate different views of an embodiment of an air purification system (e.g., an ion cluster infusing system), according to techniques of the present application.

FIGS. 3A and 3B illustrate embodiments of sensing units according the techniques of the present application.

The foregoing summary, as well as the following detailed description of certain techniques of the present application, will be better understood when read in conjunction with the appended drawings. For the purposes of illustration, certain techniques are shown in the drawings. It should be understood, however, that the claims are not limited to the arrangements and instrumentality shown in the attached drawings. Furthermore, the appearance shown in the drawings is one of many ornamental appearances that can be employed to achieve the stated functions of the system.

DETAILED DESCRIPTION OF THE APPLICATION

Referring to FIG. 1A, indoor air quality of a target environment 110 of a building 100 can be improved by monitoring at least one air quality factor of the target environment with at least with at least one air quality sensor contained in a sensing unit 130 within the target environment.

An embodiment of a sensing unit 130 is shown in FIG. 3A, and contains a radio 300 (e.g., for wirelessly communicating with other systems as described in detail below) that can communicate with a processor 310. The processor 310 can be in communication with one or more individual air sensors 320, a display 330, and a user interface 340. Another embodiment of a sensing unit 130 is shown in FIG. 3B, wherein a command module 350 (that may contain a radio, processor, user interface and/or display) is in communication with a plurality of individual air sensors 320 that may be arrayed about the command module 350.

The air quality sensors are placed in communication with the target environment. The target environment is also in communication with an air purification system 140 and at least one supply duct 125 (e.g., via a damper controller 122) of a HVAC system 120. The air purification system 140 may be optionally in communication with a supply duct 125 (e.g., via damper controller 122) of the HVAC system 120.

The HVAC system 120 can be any residential or commercial system for handling fresh air intake and conditioning to a building and can include, for example, a heating and/or air-conditioning unit or an air handler unit or exhaust units (e.g., roof-top blowers), and can be controlled by a HVAC system controller 124. The HVAC system controller 124 can be configured to control, for example, the intake air volume to the building, recirculation and exhaust volumes, and to address individual target environments within the building by, for example, adjusting dampers within building ducts to change the air volume provided through the ducts by communicating (via a wired or wireless connection) with damper controllers 122. The HVAC system 120 may include an economizer and may include an additional air purifier, such as a photo-catalytic oxidation device for operation in areas and times of high outside pollution levels.

Suitable target environments 110 include, for example, a room, a hallway, or a floor of a building or the entire building 100. Buildings include residences, hospitals, schools (e.g., classrooms or cafeterias), theaters, hotels, amphitheaters, offices, supermarkets, restaurants, warehouses, outpatient facilities, daycare facilities, health clubs (e.g., weight rooms, pools, dressing rooms), commercial buildings such as stand-alone retail, strip malls, large malls, and the like.

The air quality factor can correspond to any particulate or volatile component that may be harmful to the health of individuals in the target environment 110. For example, the target environment air quality factor can correspond to one or more air quality factors selected from the group consisting of humidity, carbon dioxide concentration, carbon monoxide concentration, radon concentration, sulfur dioxide concentration, oxygen concentration, formaldehyde concentration, NO_(x) concentration, ozone concentration, bioaerosol concentration, pathogen concentration, bacteria concentration, mold concentration, pollen concentration, and VOC concentration. Examples of VOCs include, solvents from paints or coatings, such as hydrocarbons, ethyl acetate, glycol ethers, and acetone; gasoline vapors, chlorofluorocarbons, benzene, methylene chloride, perchloroethylene, methyl tert-butyl ether (MTBE), and formaldehyde.

Suitably, the at least one air quality sensor 130 is in communication with a HVAC system controller 124 of HVAC system 120 and the air purification system 140. However, the at least one air quality sensor may be in communication with a computer 150 that is configured to control the HVAC system 120, a damper controller 122 in supply vent 125, or the air purification system 140. In any case, control of the HVAC system 120, the damper controller 122, and the air purification system 140 is based on the at least one air quality factor.

The air quality sensor 130 can be in communication with the computer 150 via a wired or a wireless connection. Computer 150 can be any computer suitable to control the air purification system 140, the HVAC system 120 via the HVAC system controller 124, or the damper controller 122, such as, a personal computer, a tablet computer (e.g., an iPad®), or a srnartphone (e.g., an iPhone®).

Then, based on the at least one air quality factor that is monitored by the air quality sensor, adjustment can be made to one or more of (a) the fresh air intake 121 on the HVAC system 120; (b) the fresh air supplied to the target environment 110 by the HVAC system 120 through the at least one supply duct 125 (for example, by adjusting a damper controller 122 or at the supply duct outlet to the target environment); and/or (c) the target environment air directed through the air purification system (for example, by opening or closing an intake opening 141 on the air purification system 140 or by increasing or decreasing the volume of target environment air directed through and out outlet opening 142 of the air purification system 140), to maintain an acceptable air quality in the target environment 110.

The monitoring and adjusting can be a periodic process based on the at least one air quality factor. By periodic it is meant that the air quality factor can be measured once every second, 5 seconds, 10 seconds, 30 seconds, 1 minute, 2 minutes, 5 minutes, 10 minutes, 15 minutes, 30 minutes, or hour, and an adjustment can be made at each time interval in response to the air quality factor.

Where an air quality factor reaches a value that is above a threshold, or the value is seen to be increasing at an unacceptable rate, then, the fresh air intake 121 on the HVAC system 120, the fresh air supplied to the target environment 110 by the HVAC system 120 through the at least one supply duct 125, and/or the target environment air directed through the air purification system 140 can be adjusted to maintain an acceptable air quality in the target environment. Suitable limits for indoor environmental contaminant levels may be set by the U.S. Environmental Protection Agency.

Advantageously, by controlling the fresh air supply to the target environment based on the preceding monitoring and adjusting, the energy consumed to maintain the air quality of the target environment can be reduced.

FIG. 1B focuses on an embodiment of the target environment 110. The air purification system 140 in the preceding can comprise the at least one air quality sensor as part of a sensing unit 130, as described above. The at least one air quality sensor can be positioned in communication with an intake opening 141 of the air purification system 140 in order to monitor the air being pulled from the target environment 110 and prior to the target environment air being pulled through the air purification system 140.

Examples of air purification systems 140 include, for example, one or more media filters, high-efficiency particulate arrestance (HEPA) filters, electrofiltration, UVGI and filter systems, gas sorption and filter systems, bipolar ionization and filter systems, photocatalytic oxidation and filter systems, and UV/ozone catalytic oxidation and filter systems, and combinations thereof. In one example, the air purification system 140 can comprises a purifier 145 for infusing ion clusters into the target environment 110, such as one or more bipolar ionization system, photocatalytic oxidation system, or UV/ozone catalytic oxidation system

The photo-catalytic oxidation (“PCO”) devices can generate ions that may have bactericidal properties, and therefore may be useful for removing bacteria, molds, viruses, or other microbes. The ions may be generated when an ultraviolet light impinges on a photo catalyst, such as TiO₂. PCO devices may use passive or active techniques to draw air from the target environment into proximity with a photo-catalytic device

A PCO device may generate ion clusters. Ion clusters may hold a relatively large amount of charge that can be effective for damaging or destroying microbes. Such ion clusters may also be relatively fragile, and devices utilizing such clusters should minimize turbulence, collisions, or contact with a conductive, grounded, or oppositely charged object or surface that may tend to damage or destroy the ion clusters.

Referring to FIG. 1C, a single target environment 110 may contain a plurality of air purification systems 143, 144, for purifying the air therein (two are shown in FIG. 1C for clarity). In such instances, at least one of the air purification systems, here denoted 143, comprises the at least one air quality sensor within a sensing unit 130 for monitoring the target environment air quality, and can be referred to as a “smart box.” The smart box 143 is in communication with at least a HVAC system controller 124 of the HVAC system 120 and optionally damper controller 122 or a computer 150 that is configured to control a HVAC system controller 124 of the HVAC system 120, damper controller 122, and the air purification systems 143, 144.

Where there are a plurality of air purification systems in a single target environment, one such system may be the smart box 143 that contains the sensing unit 130 and the second air purification systems 144 may be under the control of the smart box 143 either directly or via the computer 150. Control of the second air purification systems may be via a wired or wireless connection between smart box 143 and either the computer 150 or the second air purification systems 144. For example, a single target environment 110 may contain one smart box 143, a plurality of second air purifier systems 144 (e.g., 2, 3, 4, etc.) that are wirelessly controlled by the smart box 143 or wirelessly controlled via the computer 150 based on the air quality factor measured by the air quality sensor 130 of smart box 143.

A system is also provided that can be used for performing the methods of this application. The system can comprise (a) an air purification system comprising at least one air purifier having a housing having an intake opening and an outflow opening, wherein the housing is configured to accept a photo-catalytic oxidation device (e.g., an ion cluster generation component) that is in communication with the intake and outflow openings; and (b) at least one air quality sensor for monitoring at least one air quality factor of a target environment, wherein the air quality sensor is configured to communicate with the air purification system, a HVAC system controller, or a computer configured to monitor or control the air purification system and the HVAC system.

In particular, at least one air purifier may infuse ion clusters into a target environment and can include a housing, a fan, and an ion cluster generation component. The housing has intake and outflow openings. The housing may have a top portion and a bottom portion connected by a hinge. The fan (for example, a cross-flow blower) may be mounted to the top portion of the housing. The housing may have a sloped area between the ion cluster generation portion and the outflow opening. The housing may mounted within an opening for a 2′×2′ or a 2′×4′ ceiling tile.

The fan forces air through the intake opening and along a route. The interior surface areas of the housing adjacent to the route are electrically insulating (for example, the surface areas may be fiberglass).

The route can take either a first path or a second path. The first path goes along a straight path from the fan, through the at least one air sensor, through ion cluster generation component, and through the outflow opening.

As noted above, the at least one air quality sensor can be positioned at the intake opening of the air purification system in order to monitor the air being pulled from the target environment and through the air purifier. The at least one air quality sensor can be one or more sensors such as a humidity sensor, a carbon dioxide sensor, a carbon monoxide sensor, a radon sensor, a sulfur dioxide sensor, an oxygen sensor, a formaldehyde sensor, a NOx sensor, an ozone sensor, a bioaerosol sensor, a pathogen sensor, a bacteria sensor, a mold sensor, a pollen sensor, or a VOC sensor.

The second path goes along a first segment and a second segment. The first segment runs from the fan and through the ion cluster generation component. The second segment runs from the end of the first segment and extends downwardly through the outflow opening. The sloped area of the housing may direct air along the second segment. The interior surface areas of the housing adjacent to the route are electrically insulating (for example, fiberglass).

In particular, FIGS. 2A-2F illustrate different views of an ion infusing system 200, according to a first technique of the present application. FIGS. 2A-2C show the system 200 upside down to improve the clarity of this application. The system 200 is indicated right-side up in FIGS. 2D-2E.

FIGS. 2A and 2B show a system 200 for infusing ions, such as ion clusters, into a target environment, according to a technique of the present application. The system 200 may have a housing including a bottom portion 210 and a top portion 230. Again, these figures show the system upside down, so the bottom side 210 is depicted as being above the top side 230. The top side 230 and bottom side 210 may be connected by a connector 220, such as a hinge. The top portion 230 may include an upper surface 260, a well portion 240, and a sloped portion 250.

The bottom portion 210 may include cut-away areas. Turning to FIGS. 2E and 2F, it can be seen that such contours of the bottom portion may form openings 212 and 214. As will be further discussed, the opening 212 may be an outflow opening and the opening 214 may be an intake opening. The openings may be different sizes (as shown), may be centered (as shown with opening 214), or may be offset (as shown with opening 212).

FIG. 2C illustrates the system 200 as including a fan 270, an ion cluster generation component 280, and sensing unit 290 containing air sensors 291. Four air sensors 291 are shown for as an example and for clarity, and may be mounted to the bottom portion 210 of the system. However, any number of air sensors 291 may be present, for example 1, 2, 4, 6, 8, 10, 16, and the like in the same position, depending on the number of air quality factors to be monitored. The air sensors 291 may be positioned parallel to the flow path from the intake to output openings such that the air being sampled flows over the air sensors 291. The ion cluster generation component 280 may be a photo-catalytic oxidization (“PCO”) device. Other types of PCO devices may include radio-frequency devices, penning traps, plasmatrons, or electron cyclotron resonance devices. The fan 270 may be a cross-flow blower, a bladed fan, or a worm-drive blower.

The top portion 230 may be configured to accept the fan 270 and the ion cluster generation component 280. The well portion 240 may be able to accommodate portions of the fan 270 or the ion cluster generation component 280. The well portion 240 may also accommodate other components, such as a power bus. The fan 270 and the ion cluster generation component 280 may be mounted to the upper surface 260.

A cross-sectional illustration of the system 200 is shown in FIG. 2D. The dotted lines illustrate the flow of air when the fan 270 is operating. The fan draws or forces (for simplicity, “forces”) air in through the intake opening 214. Some of the air passes through the fan 270 and then proceeds along a route. Some of the air passes through the sensing unit 290 and over the air sensors 291 and then proceeds along a route. The route may have different possible paths.

One type of path is a substantially straight path. Such a path goes in a substantially straight line from the fan 270, through the ion cluster generation component 280, and through the outflow opening 212. Another type of path has two segments. The first segment goes from the fan 270 and through the ion cluster generation component 280. The second segment extends downwardly from the first segment and goes through the outflow opening 212. The sloped portion 250 may direct the air along the second segment. Other types of paths are also possible, such as paths that do not go through the fan 270 or the ion cluster generation component 280.

The sloped portion 250 may be at a relatively shallow angle (for example, 45° or less). By using a shallow-angled slope portion 250, it may be possible to direct ion clusters downwardly into the target environment without causing undue damage to the ion clusters through collisions or turbulence. The surface areas of the system 200 near the route may be electrically insulating. This may prevent discharge of the ion clusters before they enter the target environment. For example, the top portion 230 and the bottom portion 210 may be made from fiberglass.

FIGS. 2E and 2F illustrate two views of the system 200 when installed in a ceiling. The system is shown as located or mounted in the space for a 2′×2′ ceiling tile. The bottom portion 210 may project below the plane of the ceiling. The openings 212 and 214 may sit below the plane of the ceiling. The top portion 230 cannot be seen in FIGS. 2E and 2F because it is located above the ceiling plane in these figures.

It will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the novel techniques disclosed in this application. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the novel techniques without departing from its scope. Therefore, it is intended that the novel techniques not be limited to the particular techniques disclosed, but that they will include all techniques falling within the scope of the appended claims. 

1. A method for improving indoor air quality of a target environment comprising: monitoring, with at least one air quality sensor, at least one air quality factor of the target environment, wherein the target environment is in communication with an air purification system, the at least one air quality sensor, and at least one supply duct of an HVAC system, and the at least one air quality sensor is in communication with an HVAC system controller of the HVAC system and the air purification system; and based on the at least one air quality factor, adjusting at least one of: an air intake on the HVAC system; air supplied to the target environment by the HVAC system through the at least one supply duct; or the target environment air directed through the air purification system.
 2. The method of claim 1, wherein the at least one air quality sensor is in communication with the HVAC system controller of the HVAC system and the air purification system via a computer configured to control the HVAC system and the air purification system based on the at least one air quality factor.
 3. The method of claim 1, wherein the at least one air quality sensor is in direct communication with a supply duct of the HVAC system.
 4. The method of claim 1, wherein the air purification system comprises the at least one air quality sensor.
 5. The method of claim 1, wherein the at least one air quality factor is one or more air quality factors selected from the group consisting of humidity, carbon dioxide concentration, carbon monoxide concentration, radon concentration, sulfur dioxide concentration, oxygen concentration, formaldehyde concentration, NOx concentration, ozone concentration, bioaerosol concentration, pathogen concentration, bacteria concentration, mold concentration, pollen concentration, and VOC concentration.
 6. The method of claim 1, wherein the air purification system comprises at least one system for infusing ion clusters into the target environment.
 7. The method of claim 6, wherein the at least one air quality sensor is in direct communication with an intake opening of the air purification system.
 8. The method of claim 1, wherein the monitoring and adjusting is a periodic process based on the at least one air quality factor.
 9. The method of claim 2, wherein the least one air quality sensor is in communication with the computer via a wireless connection.
 10. The method of claim 2, wherein the least one air quality sensor is in communication with the computer via a wired connection.
 11. A system comprising: an air purification system comprising a housing including an intake opening and an outflow opening, wherein the housing is configured to accept a photo-catalytic oxidation component such that the photo-catalytic oxidation component is in communication with the intake and outflow openings; and at least one air quality sensor configured to: monitor at least one air quality factor of a target environment; and communicate with the air purification system, a HVAC system controller of a HVAC system, or a computer configured to monitor and control the air purification system and the HVAC system.
 12. The system of claim 11, wherein the at least one air quality sensor is positioned at the intake opening.
 13. The system of claim 11, wherein the at least one air quality sensor is one or more sensors selected from the group consisting of a humidity sensor, a carbon dioxide sensor, a carbon monoxide sensor, a radon sensor, a sulfur dioxide sensor, an oxygen sensor, a formaldehyde sensor, a NOx sensor, an ozone sensor, a bioaerosol sensor, a pathogen sensor, a bacteria sensor, a mold sensor, a pollen sensor, and a VOC sensor.
 14. The system of claim 11, wherein the photo-catalytic oxidation component includes an ion cluster generation component.
 15. The system of claim 11, wherein the air purifier comprises: an ion cluster generation component; a fan configured to force air through the intake opening and along a route; wherein a portion of the route comprises at least one of a first path or a second path; wherein the first path includes: a straight path from the fan, through the ion cluster generation component, and through the outflow opening; wherein the second path includes: a first segment from the fan and through the ion cluster generation component, and a second segment from the end of the first segment and extending downwardly through the outflow opening; and wherein interior surface areas of the housing adjacent to the route are electrically insulating.
 16. The system of claim 15, wherein the route comprises the first path.
 17. The system of claim 15, wherein the route comprises the second path.
 18. The system of claim 15, wherein the interior surface areas of the housing adjacent the route comprise fiberglass.
 19. The system of claim 15, wherein: the housing comprises a top portion and a bottom portion connected by a hinge; the fan is mounted to the top portion; and the top portion is configured to accept the ion cluster generation component.
 20. The system of claim 15, wherein: the housing comprises a sloped area between the ion cluster generation component and the outflow opening; and the sloped area is configured to direct air along the second segment of the second path. 